Article
Engineering, Mechanical
Y. Z. Li, Z. Y. Liang, M. X. Huang
Summary: This study investigates the effect of warm rolling on the deformation mechanisms of TWIP steel. It is found that while dislocation multiplication always controls the maximum flow stress, deformation twinning becomes increasingly important for steels with larger warm rolling reductions. The twinning kinetics is enhanced by the high dislocation densities caused by warm rolling, leading to an enhancement of twinning-induced hardening.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Nanoscience & Nanotechnology
P. H. F. Oliveira, D. C. C. Magalhaes, M. T. Izumi, O. M. Cintho, A. M. Kliauga, V. L. Sordi
Summary: This study investigated the microstructure evolution and flow behavior of a Cu-0.7Cr-0.07Zr alloy through tensile tests at different temperatures, supported by in-situ X-ray diffraction experiments. Results showed that at 298 K, dislocation glide controlled the strain-hardening rate, while at 123 K, simultaneous strength and ductility enhancement was achieved due to the TWIP effect.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Pauline Audigie, Sergio Rodriguez, Alina Aguero, Fatima Pedrosa, Teresa Paiva, Teresa C. Diamantino
Summary: This study investigated the behavior of T91 steel exposed to carbonate corrosion media under high temperature conditions. The results showed that the ISO8407 methods were more effective in removing corrosion products, while the ISO17245 method led to potential mass loss of the base material.
Article
Materials Science, Multidisciplinary
Nicolas Di Luozzo, Sandra Cabeza, Michel Boudard, Marcelo Fontana
Summary: Transient liquid phase bonding (TLPB) welding method delivers heat simultaneously to the entire joint, resulting in lower cooling rates and lower residual stress peak magnitudes. Numerical simulation through thermal and mechanical analysis can predict residual stresses in TLPB weldments.
JOURNAL OF MATERIALS SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
M. Marciszko-Wiackowska, A. Baczmanski, Ch. Braham, M. Watroba, S. Wronski, R. Wawszczak, G. Gonzalez, P. Kot, M. Klaus, Ch. Genzel
Summary: In this research, the intergranular elastic interaction and second-order plastic incompatibility stress in textured ferritic and austenitic steels were investigated using diffraction. The study found that the Eshelby-Kroner model accurately approximates the X-ray stress factors for different reflections and scattering vector orientations. The verified X-ray stress factors were then used to analyze the evolution of first and second-order stresses in both types of steel. The study also revealed that plastic deformation of about 1-2% can completely change the state of second-order plastic incompatibility stresses.
MATERIALS CHARACTERIZATION
(2023)
Article
Materials Science, Multidisciplinary
D. J. Shadle, K. E. Nygren, J. C. Stinville, M. A. Charpagne, T. J. H. Long, M. P. Echlin, C. J. Budrowf, A. T. Polonsky, T. M. Pollock, I. J. Beyerlein, M. P. Miller
Summary: Multi-modal approaches are essential for studying complex materials phenomena, as each characterization technique provides a unique perspective. Sometimes, direct interpretations between techniques are not feasible, and indirect interpretations or signatures are needed for a comprehensive understanding. In this study, signature discovery and electron and synchrotron X-ray characterization techniques were combined to identify regions of intense slip localization in an Inconel-718 alloy undergoing mechanical deformation, revealing intergranular stress states within a grain neighborhood.
MATERIALS CHARACTERIZATION
(2023)
Article
Materials Science, Multidisciplinary
Xuan Zhang, Peter Kenesei, Jun-Sang Park, Jonathan Almer, Meimei Li
Summary: The room-temperature tensile behavior of AM 316L SS was studied using high-energy X-ray diffraction and X-ray tomography. It was found that AM 316L SS exhibited high dislocation storage capability and an attractive combination of strength and ductility during plastic deformation. The morphological changes of built-in pores in AM 316L SS during deformation and fracture were also revealed to have significant roles in the material's performance.
JOURNAL OF NUCLEAR MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Kang-Mook Ryu, Dae Geon Lee, Joonoh Moon, Chang-Hoon Lee, Tae-Ho Lee, Jae Sang Lee, Dong-Woo Suh
Summary: The study found that the addition of titanium in TaTi-RAFM and EUROFER97 steels slows down hydrogen diffusion and increases its solubility in the lattice. The activation energy of hydrogen trapping increases with re-austenitization and quenching, suggesting dislocations provide trap sites with higher activation energy than Ta-rich MC carbides.
METALS AND MATERIALS INTERNATIONAL
(2021)
Article
Materials Science, Multidisciplinary
Min-Su Lee, Jeong-Rim Lee, Jong Bae Jeon, Jong Woo Won, Yong-Taek Hyun, Tea-Sung Jun
Summary: In this study, the tensile deformation behavior of CP-Ti plate was investigated in both the rolling and transverse directions using in-situ SEM-EBSD testing and stress-relaxation method. It was found that different slip systems were activated in the two directions, with prismatic slip dominant in the rolling direction and higher activity of non-prismatic slip systems in the transverse direction. Slip transfer was observed in the transverse direction, promoting multiple slips and dislocation interactions, while limited slip transfer indicated strong dislocation pinning at the grain boundaries in the rolling direction. The formation of grain boundary ledges and sinks was pronounced in the rolling and transverse directions, respectively, and they contributed to the anisotropy in the strain-hardening behavior of polycrystalline a-Ti.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Megumi Kawasaki, Jae-Kyung Han, Xiaojing Liu, Yusuke Onuki, Yulia O. Kuzminova, Stanislav A. Evlashin, Alexander M. Pesin, Alexander P. Zhilyaev, Klaus-Dieter Liss
Summary: Lab-scale X-ray diffraction and in situ heating neutron diffraction were conducted to evaluate structural changes in an additive-manufactured (AM) 316L stainless steel. The study found sequential structural relaxation and linear thermal lattice expansion in the nanostructured AM steel during heating, and observed different relaxation behaviors based on changes in crystallite sizes and dislocation densities. Furthermore, the manuscript connects critical subjects in materials science of advanced manufacturing, metal processing, and properties with novel time-resolved characterization techniques.
ADVANCED ENGINEERING MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Pramote Thirathipviwat, Sega Nozawa, Moe Furusawa, Yusuke Onuki, Makoto Hasegawa, Katsushi Matsumoto, Shigeo Sato
Summary: It is well known that variations in alloy composition and grain size can effectively improve the mechanical properties of non-heat-treatable aluminum alloys like Al-Mg alloys. This study conducted in-situ neutron diffraction experiments to investigate the evolution of dislocation density and characteristics during tensile deformation of Al-Mg. The results showed that higher Mg content and smaller grain size led to higher dislocation density, resulting in higher flow stress and strain hardening rate.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Jai Tiwari, Padma Pratheesh, O. B. Bembalge, Hariharan Krishnaswamy, Murugaiyan Amirthalingam, S. K. Panigrahi
Summary: This research investigates the electroplastic mechanism in AA 6063 alloy and its nanocomposites, revealing that SiC particles suppress the electroplastic effect. By analyzing the trend of flow stress reduction, decoupling Joule heating effects, and hypothesizing a magnetic depinning mechanism, the role of electron-dislocation interactions in plastic deformation is elucidated. The reduction in dislocation density quantified using X-ray diffraction aligns with the inferred mechanism.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Physics, Applied
Lin Lin, Cheng Ji, Yanzhang Ma
Summary: This study investigates macro strain analysis in a rotational anvil apparatus and proposes three analytical methods suitable for different applications. The validity and comparison of these methods are discussed and verified through experimental data, providing a foundation for further research on pressure shear.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Engineering, Biomedical
J. Brunet, B. Pierrat, J. Adrien, E. Maire, B. A. Lane, N. Curt, A. Bravin, N. Laroche, P. Badel
Summary: In this study, a controlled in vitro aortic dissection was performed on notched rabbit aortic segments using tension-inflation tests. Conventional and synchrotron computed tomography were used to observe the macro- and micro-structural morphological changes of the aortic wall during dissection. The study demonstrated that the morphology of the notch and the aorta can be quantified at different steps of the aortic dissection, and the notch geometry correlates with the critical pressure. The method allowed for the real-time visualization of aortic dissection propagation with unprecedented resolution.
ACTA BIOMATERIALIA
(2023)
Article
Nanoscience & Nanotechnology
Jinguang Li, Rui Hu, Mi Zhou, Zitong Gao, Yulun Wu, Xian Luo
Summary: This study analyzed the high temperature compressive process of TiNbf/TiAl composite using in situ high-energy X-ray diffraction (HEXRD) method. The results showed that both the fiber and interface play an important role in the initial deformation, but the fiber degrades at the later stage, while the load capacity of the interface remains the strongest.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Bijin Zhou, Leyun Wang, Jinhui Wang, Alireza Maldar, Gaoming Zhu, Hailong Jia, Peipeng Jin, Xiaoqin Zeng, Yanjun Li
Summary: The dislocation behavior of Mg-5Y alloy during tensile deformation was quantitatively studied using in-situ tensile test, VPSC modeling, and TEM. Results showed that <a> dislocations were the primary contributors to deformation, with a small fraction of <c+a> dislocations activated near grain boundaries. The alloy exhibited a lower CRSS ratio and high ductility, attributed to the mobility of <c+a> dislocations.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Bijin Zhou, Yanjun Li, Leyun Wang, Hailong Jia, Xiaoqin Zeng
Summary: In this study, the basal-slip-induced non-basal < a > slip behavior in a Mg-Y alloy was investigated using in-situ SEM/EBSD. It was found that the disorientation angles of grain boundaries and the plane orientation of local grain boundaries play significant roles in slip transfer behavior.
Article
Materials Science, Multidisciplinary
J. -S. Park, A. C. Chuang, J. Okasinski, H. Chen, P. Shade, T. J. Turner, S. Stock, J. Almer
Summary: This paper describes a new residual strain mapping program at the Advanced Photon Source, Argonne National Laboratory. Based on energy dispersive x-ray diffraction, the program is capable of accurately measuring the residual strain field of engineering alloys with high spatial and strain resolution, while providing a complementary view of the structure for a better understanding of the measured strain field.
EXPERIMENTAL MECHANICS
(2022)
Article
Multidisciplinary Sciences
Peihao Sun, Giulio Monaco, Peter Zalden, Klaus Sokolowski-Tinten, Jerzy Antonowicz, Ryszard Sobierajski, Yukio Kajihara, Alfred Q. R. Baron, Paul Fuoss, Andrew Chihpin Chuang, Jun-Sang Park, Jonathan Almer, J. B. Hastings
Summary: Liquid polymorphism is an interesting phenomenon observed in some single-component systems. By studying supercooled liquid Te, this research observes clear maxima in its thermodynamic response functions around a specific temperature, suggesting the possible existence of liquid polymorphism. The underlying structural evolution reveals the development of intermediate-range order, particularly around the temperature of the thermodynamic maxima, which is attributed to bond-orientational ordering. The similarities with water indicate that water-like anomalies may be a common phenomenon in liquid systems with competing bond-and density-ordering.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Materials Science, Coatings & Films
Quentin Fouliard, Hossein Ebrahimi, Johnathan Hernandez, Khanh Vo, Frank Accornero, Mary McCay, Jun-Sang Park, Jonathan Almer, Ranajay Ghosh, Seetha Raghavan
Summary: There is a growing interest in smart coatings that can be integrated into turbine engines for temperature measurements or health monitoring. This study explores the use of rare-earth dopants to create luminescent coatings that enable spectral measurements for real-time monitoring. The results showed that these coatings have minimal impact on the thermomechanical response of the thermal barrier coatings, making them a viable option for spectroscopic monitoring in extreme environments.
SURFACE & COATINGS TECHNOLOGY
(2022)
Article
Engineering, Mechanical
Matthew Northam, Quentin Fouliard, Lin Rossmann, Jun-Sang Park, Peter Kenesei, Jonathan Almer, Vaishak Viswanathan, Bryan Harder, Seetha Raghavan
Summary: The current standard application method for thermal barrier coatings (TBCs) on turbine blades for jet engines is electron-beam physical vapor deposition (EB-PVD). An emerging deposition method, plasma-spray physical vapor deposition (PS-PVD), offers a faster and less expensive alternative with a tailorable microstructure. By comparing lifetime behavior of both coatings, it was found that PS-PVD coatings showed greater variation in in-plane room temperature strain in the thermally grown oxide (TGO) layer after cycling, while both coatings exhibited similar high-temperature strain and no spallation after 600 thermal cycles. Microscopy imaging showed that PS-PVD coatings had more rumpling and different failure modes in the TGO layer compared to EB-PVD coatings. The tailorability of PS-PVD coatings enables adjustments to improve overall performance and bridge the differences between the two deposition methods.
JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME
(2023)
Article
Materials Science, Multidisciplinary
Yinbin Miao, Kun Mo, Jun-Sang Park, Jonathan Almer, Caleb Massey, Cody Havrilak, Andrew T. Nelson, Heather Connaway, Abdellatif M. Yacout
Summary: The microstructure evolution of ultrasonic additive manufactured (UAM) zirconium during room temperature uniaxial tensile straining was evaluated using the Advanced Photon Source (APS) facility. In situ synchrotron tensile tests and wide-angle X-ray scattering (WAXS) scanning were conducted to uncover the changes in microstructure. Quantification of elastic and plastic deformation mechanisms within the strained specimens was achieved using various WAXS data analysis methods. Stress concentrations identified during plastic deformation were found to be correlated with fabrication defects, providing guidance for improving the UAM zirconium fabrication process.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Chemistry, Physical
Marm B. Dixit, Bairav S. Vishugopi, Wahid Zaman, Peter Kenesei, Jun-Sang Park, Jonathan Almer, Partha P. Mukherjee, Kelsey B. Hatzell
Summary: Understanding and mitigating issues such as filament formation, short-circuiting, and solid electrolyte fracture is crucial for the development of advanced all-solid-state batteries. In this study, a combined far-field high-energy diffraction microscopy and tomography approach was used to analyze the chemo-mechanical behavior of dense, polycrystalline garnet solid electrolytes at the grain-level resolution. The results revealed that the failure mechanism is stochastic and influenced by local microstructural heterogeneity. The presence of phase heterogeneity, potentially caused by local dopant concentration variation, was observed to affect the local chemo-mechanics within the bulk solid electrolyte. These findings provide insights into the degradation process of polycrystalline garnet solid electrolytes and offer pathways for processing high-performing solid-state batteries.
Article
Materials Science, Multidisciplinary
Behnam Ahmadikia, Leyun Wang, M. Arul Kumar, Irene J. Beyerlein
Summary: By using mechanical testing, scanning electron microscopy, and a unified crystal plasticity framework, this study examines the intense and localized slip bands on prismatic planes and {1012} 1011 tensile twins in commercially pure titanium, as well as their transmission across grain boundaries. The results demonstrate that the orientation and curvature of the grain boundaries significantly affect the local stress fields and consequently the transmission of slip/twin. The neighboring grain properties, including active slip systems, slip bands, and twins, also play a crucial role in the deformation mechanisms.
Article
Nanoscience & Nanotechnology
Sheng Zhang, Gaoming Zhu, Yunhao Fan, Xiaoqin Zeng, Leyun Wang
Summary: Understanding the initiation of grain boundary (GB) damage is important for designing Mg alloys with improved ductility. In-situ tensile tests were conducted on two Mg alloy samples of different textures and GB damages were observed at 5.8% and 7.5% of the GBs before fracture. Statistical correlations between GB damage and certain GB features were identified. A machine learning model was built to predict GB damage initiation based on feature values, achieving AUC scores of 73.7% and 84.1% for the two samples. The most influential features include crystallographic c-axis misalignment, average grain size, and GB inclination with respect to the loading axis. The reasons for unpredictable GB damages are also discussed.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Zhe Song, Xiaoqin Zeng, Leyun Wang
Summary: This study investigates the influence of aluminum content on the microstructure and mechanical properties of LPBF Ti-xAl-4 V alloys. The results show that the strength of Ti-4Al-4V and Ti-8Al-4V alloys increases with increasing aluminum content, accompanied by higher work hardening and uniform elongation values compared to Ti64. This outcome is attributed to the activation of multiple slip modes in Ti44 and a more heterogeneous microstructure in Ti84.
MATERIALS RESEARCH LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Jiacheng Ge, Peng Luo, Zhenduo Wu, Wentao Zhang, Sinan Liu, Si Lan, Jonathan D. Almer, Yang Ren, Xun-Li Wang, Weihua Wang
Summary: Studying the flow behavior of amorphous solids is crucial for understanding their deformation mechanism, but detecting basic flow events in these materials is challenging. Using simultaneous SAXS/WAXS experiments, researchers have identified elementary flow carriers in wound metallic glasses, with a radius of gyration ranging from 2.5 to 3.5 nm, based on flow-induced structural heterogeneities. The size of these carriers increases and their morphology changes from spherical to rod-like during flow. Additionally, the atomic structure undergoes an unusual change to a more disordered state during winding/annealing at a temperature around 0.8 Tg. This work provides an atomic-to-nanoscale description of flow carriers in amorphous solids during deformation.
MATERIALS RESEARCH LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Yunhao Fan, Gaoming Zhu, Jun-Sang Park, Xuan Zhang, Zhe Song, Huamiao Wang, Xiaoqin Zeng, Leyun Wang
Summary: Synergy between Ca and other alloying elements can modify the microstructure and mechanical properties of Mg alloys. However, the addition of Ca did not significantly improve the tensile properties of the alloys studied. This can be attributed to the softening effect of Ca on Mg's slip systems and the offsetting of increased yield strength by reduced Al solute strengthening. Additionally, the presence of a high amount of Al compromised the texture weakening and ductility enhancement reported in Mg-Zn-Ca ternary alloys.
Article
Multidisciplinary Sciences
J. S. Park, J. D. Almer, K. C. James, L. J. Natanson, S. R. Stock
Summary: Members of subclass Elasmobranchii possess bioapatite mineralization in their cartilage skeletons, which has similar crystallography to bone but exhibits some differences. The mineral phase in shark centra has larger nanocrystallite sizes and is associated with less microstrain compared to bone.
JOURNAL OF THE ROYAL SOCIETY INTERFACE
(2022)
Article
Energy & Fuels
M. J. Connolly, J-S. Park, J. Almer, M. L. Martin, R. Amaro, P. E. Bradley, D. Lauria, A. J. Slifka
Summary: Accurate lifetime predictions are crucial for hydrogen transmission pipelines and the development of hydrogen-resistant steels. This study investigates the differences in damage modes between steels fatigued in air and in hydrogen, and discusses their impacts on lifetime predictions.
JOURNAL OF PIPELINE SCIENCE AND ENGINEERING
(2022)
Article
Materials Science, Multidisciplinary
Y. Liu, K. Zweiacker, C. Liu, J. T. McKeown, J. M. K. Wiezorek
Summary: The evolution of rapid solidification microstructure and solidification interface velocity of hypereutectic Al-20at.%Cu alloy after laser melting has been studied experimentally. It was found that the formation of microstructure was dominated by eutectic, alpha-cell, and banded morphology grains, and the growth modes changed with increasing interface velocity.
Article
Materials Science, Multidisciplinary
Bharat Gwalani, Julian Escobar, Miao Song, Jonova Thomas, Joshua Silverstein, Andrew Chihpin Chuang, Dileep Singh, Michael P. Brady, Yukinori Yamamoto, Thomas R. Watkins, Arun Devaraj
Summary: Castable alumina forming austenitic alloys exhibit superior creep life and oxidation resistance at high temperatures. This study reveals the mechanism behind the enhanced creep performance of these alloys by suppressing primary carbide formation and offers a promising alloy design strategy for high-temperature applications.
Article
Materials Science, Multidisciplinary
Jian Song, Qi Zhang, Songsong Yao, Kunming Yang, Houyu Ma, Jiamiao Ni, Boan Zhong, Yue Liu, Jian Wang, Tongxiang Fan
Summary: Recent studies have shown that achieving an atomically flat surface for metals can greatly improve their oxidation resistance and enhance their electronic-optical applications. Researchers have explored the use of graphene as a covering layer to achieve atomically flat surfaces. They found that high-temperature deposited graphene on copper surfaces formed mono-atomic steps, while annealed copper and transferred graphene on copper interfaces formed multi-atomic steps.
Article
Materials Science, Multidisciplinary
Jennifer A. Glerum, Jon-Erik Mogonye, David C. Dunand
Summary: Elemental powders of Al, Ti, Sc, and Zr are blended and processed via laser powder-bed fusion to create binary and ternary alloys. The microstructural analysis and mechanical testing show that the addition of Ti results in the formation of primary precipitates, while the addition of Sc and Zr leads to the formation of fine grain bands. The Al-0.25Ti-0.25Zr alloy exhibits comparable strain rates to Al-0.5Zr at low stresses, but significantly higher strain rates at higher stresses during compressive creep testing. Finite element modeling suggests that the connectivity of coarse and fine grain regions is a critical factor affecting the creep resistance of the alloys.
Article
Materials Science, Multidisciplinary
P. Jannotti, B. C. Hornbuckle, J. T. Lloyd, N. Lorenzo, M. Aniska, T. L. Luckenbaugh, A. J. Roberts, A. Giri, K. A. Darling
Summary: This work characterizes the thermo-mechanical behavior of bulk nanocrystalline Cu-Ta alloys under extreme conditions. The experiments reveal that the alloys exhibit unique mechanical properties, behaving differently from conventional nanocrystalline Cu. They do not undergo grain coarsening during extrusion and exhibit behavior similar to coarse-grained Cu.
Article
Materials Science, Multidisciplinary
Yiqing Wei, Jingwei Li, Daliang Zhang, Bin Zhang, Zizhen Zhou, Guang Han, Guoyu Wang, Carmelo Prestipino, Pierric Lemoine, Emmanuel Guilmeau, Xu Lu, Xiaoyuan Zhou
Summary: This study proposes a new strategy to modify microstructure by phase regulation, which can simultaneously enhance carrier mobility and reduce lattice thermal conductivity. The addition of Cu in layered SnSe2 induces a phase transition that leads to increased grain size and reduced stacking fault density, resulting in improved carrier mobility and lower lattice thermal conductivity.
Article
Materials Science, Multidisciplinary
Jia Chen, Zhengyu Zhang, Eitan Hershkovitz, Jonathan Poplawsky, Raja Shekar Bhupal Dandu, Chang-Yu Hung, Wenbo Wang, Yi Yao, Lin Li, Hongliang Xin, Honggyu Kim, Wenjun Cai
Summary: In this study, the structural origin of the pH-dependent repassivation mechanisms in multi-principal element alloys (MPEA) was investigated using surface characterization and computational simulations. It was found that selective oxidation in acidic to neutral solutions leads to enhanced nickel enrichment on the surface, resulting in reduced repassivation capability and corrosion resistance.
Article
Materials Science, Multidisciplinary
X. Y. Xu, C. P. Huang, H. Y. Wang, Y. Z. Li, M. X. Huang
Summary: The limited slip systems of magnesium (Mg) and its alloys hinder their wide applications. By conducting tensile straining experiments, researchers discovered a rate-dependent transition in the dislocation mechanisms of Mg alloys. At high strain rates, glissile dislocations dominate, while easy-glide dislocations dominate at low strain rates. Abundant glissile dislocations do not necessarily improve ductility.
Article
Materials Science, Multidisciplinary
M. S. Szczerba, M. J. Szczerba
Summary: Inverse temperature dependences of the detwinning stress were observed in face-centered cubic deformation twins in Cu-8at.%Al alloy. The detwinning stress increased with temperature when the pi detwinning mode was involved, but decreased when the pi/3 mode was involved. The dual effect of temperature on the detwinning stress was due to the reduction of internal stresses pre-existing within the deformation twins. The complete reduction of internal stresses at about 530 degrees C led to the equivalence of the critical stresses of different detwinning modes and a decrease in the yield stress anisotropy of the twin/matrix structure.
Article
Materials Science, Multidisciplinary
Taowen Dong, Tingting Qin, Wei Zhang, Yaowen Zhang, Zhuoran Feng, Yuxiang Gao, Zhongyu Pan, Zixiang Xia, Yan Wang, Chunming Yang, Peng Wang, Weitao Zheng
Summary: The interaction between the electrode and the electric double layer (EDL) significantly influences the energy storage mechanism. By studying the popular alpha-Fe2O3 electrode and the EDL interaction, we find that the energy storage mechanism of the electrode can be controlled by modulating the EDL.
Article
Materials Science, Multidisciplinary
Matthew R. Barnett, Jun Wang, Sitarama R. Kada, Alban de Vaucorbeil, Andrew Stevenson, Marc Fivel, Peter A. Lynch
Summary: The elastic-plastic transition in magnesium alloy Mg-4.5Zn exhibits bursts of deformation, which are characterized by sudden changes in grain orientation. These bursts occur in a coordinated manner among nearby grains, with the highest burst rate observed at the onset of full plasticity. The most significant burst events are associated with twinning, supported by the observation of twinned structures using electron microscopy. The bursts are often preceded and followed by a stasis in peak movement, indicating a certain "birth size" for twins upon formation and subsequent growth at a later stage.
Article
Materials Science, Multidisciplinary
Vaidehi Menon, Sambit Das, Vikram Gavini, Liang Qi
Summary: Understanding solute segregation thermodynamics is crucial for investigating grain boundary properties. The spectral approach and thermodynamic integration methods can be used to predict solute segregation behavior at grain boundaries and compare with experimental observations, thus aiding in alloy design and performance control.
Article
Materials Science, Multidisciplinary
Feiyu Qin, Lei Hu, Yingcai Zhu, Yuki Sakai, Shogo Kawaguchi, Akihiko Machida, Tetsu Watanuki, Yue-Wen Fang, Jun Sun, Xiangdong Ding, Masaki Azuma
Summary: This study reports on the negative and zero thermal expansion properties of Cd2Re2O7 and Cd1.95Ni0.05Re2O7 materials, along with their ultra-low thermal conductivity. Through investigations of their structures and phonon calculations, the synergistic effect of local structure distortion and soft phonons is revealed as the key to achieving these distinctive properties.
Article
Materials Science, Multidisciplinary
Thomas Beerli, Christian C. Roth, Dirk Mohr
Summary: A novel testing system for miniature specimens is designed to characterize the plastic response of materials for which conventional full-size specimens cannot be extracted. The system has an automated operation process, which reduces the damage to specimens caused by manual handling and improves the stability of the test results. The experiments show that the miniature specimens extracted from stainless steel and aluminum have high reproducibility, and the results are consistent with those of conventional-sized specimens. A correction procedure is provided to consider the influence of surface roughness and heat-affected zone caused by wire EDM.
Article
Materials Science, Multidisciplinary
Rani Mary Joy, Paulius Pobedinskas, Nina Baule, Shengyuan Bai, Daen Jannis, Nicolas Gauquelin, Marie-Amandine Pinault-Thaury, Francois Jomard, Kamatchi Jothiramalingam Sankaran, Rozita Rouzbahani, Fernando Lloret, Derese Desta, Jan D'Haen, Johan Verbeeck, Michael Frank Becker, Ken Haenen
Summary: This study investigates the influence of film microstructure and composition on the Young's modulus and residual stress in nanocrystalline diamond thin films. The results provide insights into the mechanical properties and intrinsic stress sources of these films, and demonstrate the potential for producing high-quality nanocrystalline diamond films under certain conditions.
